X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fonion_utils.rs;h=e952bd8e2e125c5d8c16ef6f8419e1c8a2579ba0;hb=98544772e2d5bd28f68a0e485dfe2eafed186cab;hp=9af3de07ff4e7356ac65fe2069b3ff209761156a;hpb=0e83e91d7ae6e402ca24164e920cf12b486cd17c;p=rust-lightning

diff --git a/lightning/src/ln/onion_utils.rs b/lightning/src/ln/onion_utils.rs
index 9af3de07..e952bd8e 100644
--- a/lightning/src/ln/onion_utils.rs
+++ b/lightning/src/ln/onion_utils.rs
@@ -93,7 +93,7 @@ pub(super) fn gen_pad_from_shared_secret(shared_secret: &[u8]) -> [u8; 32] {
 }
 
 /// Calculates a pubkey for the next hop, such as the next hop's packet pubkey or blinding point.
-pub(crate) fn next_hop_pubkey<T: secp256k1::Signing + secp256k1::Verification>(
+pub(crate) fn next_hop_pubkey<T: secp256k1::Verification>(
 	secp_ctx: &Secp256k1<T>, curr_pubkey: PublicKey, shared_secret: &[u8]
 ) -> Result<PublicKey, secp256k1::Error> {
 	let blinding_factor = {
@@ -935,6 +935,27 @@ pub(crate) fn decode_next_payment_hop<NS: Deref>(
 	}
 }
 
+/// Build a payment onion, returning the first hop msat and cltv values as well.
+/// `cur_block_height` should be set to the best known block height + 1.
+pub fn create_payment_onion<T: secp256k1::Signing>(
+	secp_ctx: &Secp256k1<T>, path: &Path, session_priv: &SecretKey, total_msat: u64,
+	recipient_onion: RecipientOnionFields, cur_block_height: u32, payment_hash: &PaymentHash,
+	keysend_preimage: &Option<PaymentPreimage>, prng_seed: [u8; 32]
+) -> Result<(msgs::OnionPacket, u64, u32), APIError> {
+	let onion_keys = construct_onion_keys(&secp_ctx, &path, &session_priv)
+		.map_err(|_| APIError::InvalidRoute{
+			err: "Pubkey along hop was maliciously selected".to_owned()
+		})?;
+	let (onion_payloads, htlc_msat, htlc_cltv) = build_onion_payloads(
+		&path, total_msat, recipient_onion, cur_block_height, keysend_preimage
+	)?;
+	let onion_packet = construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash)
+		.map_err(|_| APIError::InvalidRoute{
+			err: "Route size too large considering onion data".to_owned()
+		})?;
+	Ok((onion_packet, htlc_msat, htlc_cltv))
+}
+
 pub(crate) fn decode_next_untagged_hop<T, R: ReadableArgs<T>, N: NextPacketBytes>(shared_secret: [u8; 32], hop_data: &[u8], hmac_bytes: [u8; 32], read_args: T) -> Result<(R, Option<([u8; 32], N)>), OnionDecodeErr> {
 	decode_next_hop(shared_secret, hop_data, hmac_bytes, None, read_args)
 }